1. Field of the Invention
The present invention relates to methods for predicting and controlling the shrinkage of ceramic oxides during firing.
2. Description of the Prior Art
A relatively recent innovation in electronic packaging has been the development of the multilayer ceramic (hereinafter MLC) module. In this technology "green" sheets of ceramic powder held together by a temporary organic binder are metallized with a noble or refractory metal, usually, but not mandatorily, by screen printing. The metallized sheets are stacked, laminated and fired to form a monolithic ceramic-metal package. Details on MLC technology are given in SOLID STATE TECHNOLOGY, May 1972, Vol. 15, No. 5, pages 35-40, Kaiser et al, hereby incorporated by reference.
U.S. Pat. No. 4,052,538, Eddy et al, discloses a method of forming sintered sodium beta-alumina articles by forming an aqueous acidic colloidal solution (sol) of a dispersable alpha-alumina mono-hydrate, adding an aqueous solution of an inorganic oxygen-containing sodium salt to the sol to form a thixotropic gel, spray drying to form a free flowing powder, pressing into an article, heating to drive off volatile material and then sintering to form a densified sodium beta-alumina structure.
U.S. Pat. No. 4,265,669, Starling et al, discloses a hard, strong ceramic body, a ceramic raw batch and a method for manufacture. The body, after being formed of the raw batch, can be fired to a monolithic structure without any shrinkage or distortion during the firing operation. The raw batch contains aluminum oxide, magnesium oxide, glass frit and a silicone resin.
U.S. Pat. No. 4,316,965, Oda et al, discloses low expansion ceramics and methods of producing the same. These ceramics comprise defined proportions of MgO, Al.sub.2 O.sub.3, TiO.sub.2, SiO.sub.2 and Fe.sub.2 O.sub.3. The major component of the crystalline phase is a solid solution of magnesium oxide-aluminum oxide-titanium dioxide-silicon oxide-iron oxide. The method comprises preparing a batch, plasticizing the batch if necessary, shaping, drying and firing at a defined temperature. The resulting products have a honeycomb structure.